Microglia are the resident immune cells in the central nervous system (CNS). Originally thought to be primarily responsible for disposing of cellular debris and responding to neural insults, emerging research now shows that microglia are highly dynamic cells involved in a variety of neural processes, including development. The hypothalamus is a brain region critical for maintaining homeostatic processes such as energy balance, thirst, food intake, reproduction, and circadian rhythms. Given that microglia colonize the embryonic brain alongside key steps of hypothalamic development and that the loss of microglia causes newborn pups to be obese, consistent with a defect in neuroendocrine signaling, we sought to explore whether microglia themselves can influence these nearby hypothalamic progenitors. In this talk I will discuss some of our recent findings demonstrating that microglia can interact with hypothalamic radial glial projections and influence overall development of this important brain region. Our data suggest that microglia regulate hypothalamic embryonic development.